Conventionally, a chair-type massage machine having a backrest portion being capable of reclining, a seat portion, and an armrest portion is widely known. Such a chair-type massage machine is provided with a kneading ball actuated by electric power for massaging the lower back portion, the back portion, the neck portion, the seat portion, and the arm portion of the human body and/or a bag body which expands or contract by a change of air pressure using compressed air.
For example, a seat portion to be seated and an armrest portion provided at the both sides of the seat portion for treating the both arms of a person to be treated are disclosed. It is also disclosed as one aspect that an inner erection wall and an outer erection wall composing the armrest portion are provided with keeping a predetermined space from each other.